I haven't seen Edward Dutton but will look later today. I like the IQ drop theory though and might agree. I have a little sci fi novel on my shelf "IQ 88" & will review today to find out WHY IQ dropped in the novel, and WHY Dutton proposes this. My own reason would be INTENTIONAL poisoning via sodium fluoride in the water, as one means. Other INTENTIONAL attacks on IQ can be done by soil-mineral nutrient depletion. Finally, there is this by another Ed:

Warning from Ed Dowd: 7,500 Americans are killed or disabled EACH DAY as vax jabs take heavy toll… USA imploding under “decivilization” assault
Ed Dowd / Mike Adams
https://tinyurl.com/mpnkcv35